My Sentinel is pretty simple, and I can't imagine setting one up particularly different:
2 ranks of Throw
4 ranks of Warp
4 ranks of Tech Armor
4 ranks of Overload
0 ranks of Cryo Blast
4 ranks of the passive skill
Remaining points into AP Ammo. (Warp ammo might be a better choice, but I haven't done Jack's mission yet.)
I played around with Reave as the bonus skill (moving all my points from Warp to Reave) for a while, and I do think that it's a more useful ability, but it still is 80% similar to Warp, and thus not the best use of the bonus skill spot. Also, the ammo powers are effective even with a minimal investment (1 rank of AP ammo = +30% gun damage to armor and health).
Anyhow, I really don't see much room for any different-but-equally-effective builds. I guess one could max out Throw or Cryo Blast for crowd-control of un-armored/shielded/barriered enemies, but such a build would be relatively less effective in most fights. A different bonus skill like Slam or Neural Shock might make for marginal tactical changes, too. But really, I think that all Sentinels are going to play pretty much the same way once they're past the first few levels.